Historically, consumer telephones and computing devices were tethered to telecommunications networks via one or more communication cables. Within the past few decades, the reduced cost and size of electronics devices, improved and standardized communications technologies, and capital investments in communications infrastructure have enabled the widespread use of mobile voice and data communications devices that operate wirelessly using radio signals. The use of mobile telecommunications has grown so rapidly that wireless communications devices, such as cellular telephones, wireless personal digital assistants (PDA), and wireless laptop computers, are ubiquitous in today's industrialized countries. To communicate, these devices transmit and/or receive audio, video, and/or data over wireless communications networks, like cellular, satellite, or WIFI networks.
The wireless communications service providers that operate these wireless communications networks provide subscribed services to the users of the wireless communications devices by providing for registration, authentication, location updating, handovers, call routing, etc.
The most widespread wireless communication network in use today is that of cellular telephones. However, not all cellular telephone networks communicate using the same standards. The most popular standard is the Global System for Mobile communications (GSM), which is implemented by communications service providers in over 200 countries and territories. This allows GSM subscribers to use their cellular telephones and other GSM data communications devices in many parts of the world. GSM specifies standards for voice communications and also for Short Message Service (SMS) text messaging, General Packet Radio Service (GPRS) packet data communications, and Enhanced Data Rates for GSM Evolution (EDGE) higher-speed data communications.
GSM provides subscriber verification and authentication, and encrypts communications between subscribers and the remainder of the telecommunications network. A Subscriber Identity Module (SIM), a detachable electronics card, stores the subscriber's International Mobile Subscriber Identity (IMSI), individual subscriber authentication key (Ki), ciphering key (Kc), and personal information such has the subscriber's phonebook. The IMSI is composed of a Mobile Country Code (MCC), a Mobile Network Code (MNC) and a subscriber-specific Mobile Subscriber Identity Number (MSIN).
The portability of SIM cards allows subscribers to easily swap SIM cards between GSM compatible devices and continue to use the communications network using the subscriber account associated with their SIM card.
A key GSM feature is roaming, the ability for a mobile customer to automatically make and receive voice calls, send and receive data, or access other services, including data services, when traveling outside the geographical coverage area of the home network. Roaming is supported by mobility management, authentication, authorization and billing procedures agreed upon by the various service providers. A subscriber's home network is the one where the mobile communications device is registered in the Home Location Register (HLR). When a mobile communications device is powered on or transferred to a network, using the IMSI, the network determines whether the station is registered in its HLR. If it is, the network is the subscriber's home network and communications proceed. If the mobile communications device is not registered, the visited network attempts to identify the device's home network, and then requests service information about the mobile communications device. If there is no roaming agreement between the two service providers, or if the mobile communications device is not allowed to roam, the visited network denies service. If service is allowed, the visited network establishes a Temporary Mobile Subscriber Identity (TMSI) and begins to maintain a service record. The home network updates its information to indicate that the mobile communications device is on the visited network, its new host network, so any information sent to it can be routed correctly. When a call is made to a roaming mobile communications device, the Public Switched Telephone Network (PSTN) routes the call to the station's home network, which then routes it to the visited network.
Although roaming provides necessary capabilities, it works only when the home and visited network use the same communications technologies and have a roaming agreement. Also, roaming fees, especially international fees, can be costly. Furthermore, from the subscriber's viewpoint roaming fees can appear unjustified, for example, when one member of a group of business travelers or tourists from the same home network calls another in the same visited network. To circumvent such difficulties, some subscribers purchase, rent or borrow SIM cards or mobile communications devices with SIM cards, for the visited or foreign network. For example, a traveler from the U.S. to the U.K. might rent or buy a SIM card or cellular telephone from a vendor in London. Purchasing and swapping-out SIM cards is inconvenient, inefficient, and technically challenging for most subscribers, especially when traveling to multiple foreign countries. This approach also does not support incoming calls to the subscriber's regular cellular phone number. Moreover, most subscribers purchase prepaid SIM cards for a set amount and may either run out of prepaid communication time on the card or pay for communication time that they do not end up using.
As such, a system and method that allows users to easily travel between networks without being charged excessive roaming charges would be highly desirable.
Furthermore, in the case of wireless data services, like WIFI or WIMAX, users may connect to remote wireless access points or “hotspots” by paying a monthly or hourly fee. Monthly fees typically cost less per hour than the hourly fee system, but users may not fully utilize the network for the entire period. As such, a system and method that allows users to easily roam between networks, not be charged excessive charges, and simplify all charges into a single invoice would be highly desirable.